Drill pipe protector



Jan. 4, 1966 C. H. LEATHERS DRILL PIPE PROTECTOR Jan. 4, 1966 c. H. LEATHERS 3,227,498

DRILL PIPE PROTECTOR y Filed April 5, 1963 2 Sheets-Sheet z INVENTOR CLARENCE H. LEATHERS Y BY ive/m; Q/,zgom

ATTORNEYS United States Patent O 3,227,498 DRILL PIPE PROTECTR Clarence H. Leathers, Redondo Beach, Calif., assigner to Grant Gil Tool Company,Los Angeles, Calif., a corporation of California Filed Apr; 3, 1963; Ser. No. 270,422 3 Claims.A (Cl.\3084) This invention relates to drill pipe protectors which are adapted to be attached to rotary drill strings and more particularly to an improved form of protector which is radially removable from the section of the drill string upon which i-t is mounted.

In a drilling operation it is frequently necessary to mount drill pipe protectors on a drill string to prevent abrasion and damage to the drill pipe. This isparticularly true in the cased `section of a hole since rotation of the drill string against the interior wall of the casing will cause damage to the drill pipe. Inasmuch as drill pipe is expensive and reusable it is essential to prevent damage to the pipe in order that it can be used as many times as possible. In the prior state of th-e art, the most common type of drill pipe protector is the type which rotates with the drill string. Typical types are those mad-e of rubber which are stretched over the enlarged end of a l section of the pipe. This type is placed over the enlarged end with an expanding tool, the protector being sufliciently small in inside diameter so that when the expanding tool is removed the protector will rmly engage the pipo while the outside diameter is greater than the diameter of the pipe joint. The protector thus rotates with the pipe .and prevents the pipe from contacting the casing. An-

other typical protector is the type which is latched onto they pipe section in a stretched condition and retained by a hinge pin or the like. These protectors have various disadvantages particularly in that they rotate with the pipe and are dilicult to quickly position on the pipe. During drilling operations `it is essential `that the protectors be placed on or removed from the drill string quickly and efficiently.

Accordingly, it is an object of the present invention to provide improved drill string protectors.

It is another object of thepresent invention to provid-e a drill string protector which is detachably mounted directly to the drill pipe.

It is a further object of the present invention to provide a detachable drill string protector which is simple in construction.

It is a still further object of the present invention to provide an improved detachably mounted drill string protector which does not require disconnection of the sections `of the drill string for removal.

It is yet another object of the present invention to provide an improved drill string protector which is free to rotate on the drill pipe.

It is also an object of the present invention to provide an improved detachable drill string protector for use inside both cased and open holes which is free to travel along the string. between tooljoints.

In its presently preferred form, the drill string protector in accordance with the present invention comprises a cylinder formed of rst and second arcuate sections which are matable and which will in the cylindrically mated condition of the sections be iirmly interlocked one with the other. The iirst arcuate section is greater than 180 in extent while the second arcuate section is less than 180. The inner diameter of the cylinder formed by the mated sections is slightly larger than the diameter of the drill pipe so that the bushing is free to rotate on the pipe. The outer diameter of the cylinder is greater than the diameter of the tool joints intercoupling the drill pipe sections so 3,227,498 Patented Jan. 4, 1966 "ice that the protector extends radially beyond the diameter of the tool joints in the drill string. To mount the protector the ends of the tirst arcuate section are expanded sutliciently that the chord between the ends is greater in length than the diameter of the drill pipe and the first section is slipped over the drill pipe. The ends are then allowed to return to their normally urged position to engage the ends of the second section to firmly retain the second section in engagement with the irst section.

The novel features which are believed to be characteristic of the invention both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawing in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only and it is not intended as a definition of the limits of the invention.

In the drawing:

FIGURE 1 is a vertical section taken through an illustrative drill bore and showing an exemplary drill string with a protector in accordance with the present invention mounted thereon;

FIGURE 2 is a plan view partly in section of the presently preferred form of the present invention;

FIGURE 3 is a View in elevation partly in section taken along line 3 3 of FIGURE 2;

FIGURE 4 is a view in perspective of the metal sleeve of the rst section of the protector as shown in FIGURES 2 and 3 removed from the protector for purposes of explanation;

FIGURE 5 is a view of a type of tool used for placing a protector in accordance with the present invention on a drill pipe and removing it therefrom; and

FIGURE 6 is a perspective View with parts in section and in phantom line of the protector of FIGS. 1 5.

Referring now to the drawing, there is shown in FIG- URE l a drill pipe protector 2li in accordance with the present invention mounted on a drill string 1t) within a vertical well bore 15. The drill string 1i) is composed of a `plurality of drill pipe sections llt-longitudinally intercoupled by means of tool joints l2. Each section of drill pipe has a tool joint at its ends, one end being male threaded and the other end being female threaded as is well known in the art. The well bore 15 as shown in FIGURE 1 is a cased hole, although the protector of the present invention is equally suitable for use in open hole well bores; Referring now particularly to FIG- URES 2, 3 and 4 the construction of the protector in accordance with the presently preferred embodiment of the present invention is shown and comprises generally a lirst section designated Section A and a second section designated generally Section B, which sections when mated about the drill pipe form a cylinder which is longitudinally extending relative to the drill pipe as shown in FIGURE l. The assembled protector shown in FIG- URES 2 and 3 has an inside diameter 2l slightly greater than the outside diameter of the drill pipe 10 but less than-the diameter of the tool joint 12. The outside diameter 22 is greater than the outermost diameter of the tool joint l2. Both the exterior surface and the interior surface of the cylindrical protector are provided with a plurality of radially spaced tintes 23 on the outside diameter and 24 on the inside diameter to allow for the passage of fluid. The passage of fluid along the inside surface is particularly desirable for lubricating effect. The protector when assembled into cylindrical form includes a metal sleeve C comprising a first arcuate section 25 and a second arcuate section 26 as described more fully hereinafter. Surrounding the metal sleeve C is a aast/,49a

substantial thickness of elastomeric material including an outer section 27 which extends from the outer diameter of the sleeve to the outer diameter of the protector and which is of sufiicient thickness to allow the flutes 23 to be formed therein and an inner section 28 of elastomeric material which extends inwardly from the inner diameter of the metal sleeve C. Thus, as shown in particularity in FIGURES 2 and 3 the first and second sections of the metal sleeve are imbedded in eiastomeric material which material is split as described more fully hereinafter so that when the sections of the protector are assembled the elastomeric material also mates to form a complete cylinder surrounding the sleeve and extending slightly beyond the sleeve at the ends thereof so that in the assembled condition the metal sleeve is completely encapsulated in the elastomeric material. The upper and lower ends of the elastomeric cylinder are tapered as at 29 in FIGURE 3 to allow the movement of the protector upwardly and downwardly on the drill pipe.

Referring now particularly to FIGURES 2 and 4 the first arcuate section of the metal sleeve C is shown removed from the elastomeric material in FIGURE 4. As can be seen from the figures the arcuate extent of the first section is greater than 180 such that when the first portion of the protector is in position on the drill pipe it cannot be removed therefrom without deformation of the first arcuate section. For reference, lines 33 and 34 can be considered as dividing line between the first and second arcuate sections. In the embodiment shown the dividing lines 33 and 34 are substantially a tangent to the inside diameter 21 of the protector at opposite ends of a common diameter of the protector and are thus parallel and spaced apart by the length of the inner diameter. The inner ends 37 and 3S of the arcuate sleeve section 25 extend beyond the tangential lines 33 and 34 by a substantial amount and thus define an opening between such ends which is a chord having a length substantially less than the inside diameter of the protector and less than the outside diameter of the drill pipe. The ends 37 and 38' (see also FIG. 6) are tapered and the sleeve is formed of material such as spring steel which can be deformed to spread the ends 37 and 38 apart. The section is of suflicient rigidity and thickness, however, that the ends are urged to the normal position by a strong force. The second arcuate section 26 of the sleeve C is mateable with the first section 25 to form a full cylinder as shown in FIGURE 2. The lateral ends 39 and 40 of the second arcuate section extend beyond the tapered ends 37 and 38 of the first section but define longitudinal grooves 41 and 42 in the end surfaces into which the tapered ends 37 and 38 are mateable, as shown in FIG. 6. Referring particularly to FIGURE 4, notches 43 and 44 are formed in the end surfaces 37 and 38 of the section 25 approximately midway along the longitudinal extent of the end surfaces. These notches are for assembly and disassembly of the protector upon the drill pipe as more fully described hereinafter. The notches are formed to include pry surfaces 45-46 which face inwardly and provide opposed bearing surfaces against which a spreading force can be exerted. Reinforcing bars 47 are affixed to the outer surface of the section 25 opposite the pry surfaces to prevent deformation of the sleeve when force is applied to the pry surfaces.

Elastomeric material is molded about both arcuate sections to form the nished protector cylinder with fiuted surfaces as previously described. The elastomeric material forming the cylinder is applied to the two arcu- CII ate sections such that it is divided along the dividing line 33. Openings 48 and 49 through the elastomeric sections are provided for access to the sleeve sections A and B for assembly and disassembly. As can be seen in FIG- URES 2 and 3 the openings are approximately midway along the length of the protector and correspond to the notches 43 and 44 for access thereto.

Thus, when it is desired to place the protector on a section of drill pipe 11 as in FIGURE 1 the first section A of the protector is positioned with the ends 37 and 38 adjacent the pipe. A spreading tool 60 such as shown in FIGURE 5 is opened and placed around the drill pipe. The ends 6l of the tool 60 are then placed through the openings 48 and the bearing surfaces 62 of the tool are brought into contact with the pry surfaces and 46 of the sleeve section 25. The tool is opened by turning crank 63 to spread the ends 61 to in turn force the pry surfaces 45 and 46 apart until the sleeve ends 37 and 3S are apart by a distance greater than the diameter of the drill pipe. The Section A with the tool in place is then moved to surround the drill pipe. Section B is placed into position with openings 49 allowing insertion past the tool 60. The tool is then closed allowing the ends 37 and 33 of the sleeve section 25 to return to the normal position and mate with the grooves 41 and 42 in the second sleeve section 26. This is shown in FIG. 6, wherein a part of the molded elastomeric material has been omitted for clarity. The tool is removed and the protector is thus firmly held in the .assembled condition of FIGURE 2. The protector is removed from the drill pipe by the opposite procedure or by forcing the sections apart with a jack or similar means.

What is claimed is:

1. A drill string protector adapted to be rotatably positioned on a drill string between tool joints at opposite ends of a section of drill pipe comprising a cylinder comprising first and second longitudinally extending arcuate sections, said cylinder having an inside diameter substantially equal to but greater than the outside diameter of said drill pipe, said second section being less than arcuate extent and having spaced longitudinally extending groove means, said first section being resilient and 0f greater than 180 arcuate extent and engaging said groove means and firmly holding said second section, whereby said sections are held in assembled relation to define said cylinder, said first section being deformable to an expanded condition at which the arcuate ends of said first section are spaced apart by a distance greater than the outside diameter of said drill pipe.

Z. A drill string protector as set forth in claim 1, said sections comprising elastomeric material surrounding metal members.

3. A drill string protector as set forth in claim 1, said groove means extending along the lateral ends of said second section.

References Cited by the Examiner UNITED STATES PATENTS 2,594,587 4/1952 Riordon 308-237 2,739,018 3/1956 Collett 308-4 2,813,697 1l/l957 Swart 308-4 DAVID I. WILLIAMOWSKY, Primary Examiner.

ROBERT C. RIORDON, Examiner.

L. L. JOHNSON, Assistant Examiner. 

1. A DRILL STRING PROTECTOR ADAPTED TO BE ROTATABLY POSITIONED ON A DRILL STRING BETWEEN TOOL JOINTS AT OPPOSITE ENDS OF A SECTION OF DRILL PIPE COMPRISING A CYLINDER COMPRISING FIRST AND SECOND LONGITUDINALLY EXTENDING ARCUATE SECTIONS, SAID CYLINDER HAVING AN INSIDE DIAMETER SUBSTANTIALLY EQUAL TO BUT GREATER THAN THE OUTSIDE DIAMETER OF SAID DRILL PIPE, SAID SECOND SECTION BEING LESS THAN 180* ARCUATE EXTENT AND HAVING SPACED LONGITUDINALLY EXTENDING GROOVE MEANS, SAID FIRST SECTION BEING RESILIENT AND OF GREATER THAN 180* ARCUATE EXTENT AND ENGAGING SAID GROOVE MEANS AND FIRMLY HOLDING SAID SECOND SECTION, WHEREBY SAID SECTIONS ARE HELD IN ASSEMBLED RELATION TO DEFINE SAID CYLINDER, SAID FIRST SECTION BEING DEFORMABLE TO AN EXPANDED CONDITION AT WHICH THE ARCUATE ENDS OF SAID FIRST SECTION ARE SPACED APART BY A DISTANCE GREATER THAN THE OUTSIDE DIAMETER OF SAID DRILL PIPE. 